Process for producing artificial silk in the form of spun cakes



Patented Mar. 26 v I s V Q i 1,996,017; I

J PROCESS FOR, PRODUCING ARTIFICIAL L I T FQ PUN Qe Franz --Hoelkeskamp',- Wuppertal Wicjh:linghausen,

e 1 vGermamzassignorto American 'Bemberg :Corp'oration, New York, N- Y.,aj corporation .of Delaware; w i

, No Drawing; "Application December 17, 1 1930, j

g figal -No'.-502,98 8 In Germany December f .:s Claime (01,1844; r

' the spinning of artificial silk hitherto'spim' cilitated, since the accuracy" of- ;the;mounting ning pots were used which usually had anjinterneed not be -so;high in the case of lower rota-- nal diameter of 15-20 cm. and rotated atjabout; vtional speeds, for the forces acting on the'bear- 6,000 revolutions. These, spinning pots were ings producingunevenrunning increase COIlSid-r.

5 ioundtobethoroughly reliable in. the-production erably with rising-rotational speed.,-v p j M H ofertificial silk of the usualttitre if attention, After spinning-, the precipitates are dissolved was paid, to their carefulmounting which en i during the after-treatmentbysuitable agents, suredsmooth runningand satisfactory. spin-- such as acids andremoved from the filaments ning at the requisite high rotational speed, bywashing. --In the processes heretofore known 159 However, if finer titres are spun, for example after-treatment with :acid or theglike was also lo according tothecuprammonium stretch-spinnecessarysso that the process according tpgthis f ning process, it is found that the winding up invention is no more bothersome. into spun cakes cannot any longer be effected Theprocess will now be described in greater freefrom trouble in the case ofyarn of 60 deniers detail by reference to some examples. j l

and less. The filaments are drawn into the spinf The individual filaments of cuprammonium' ld ning' pot badly or not at all. 1 These disadvanoxide issuing from the nozzle into a spinning vestages would be avoided by raising the speedof sel with flowing water as precipitating liquor revolution, but bearing in mind security 1 in are precipitated and leave the spinningvessel I mounting, this is not possible. However, even with a considerable copper hydroxide content.

in' the case'of the usual titres, a diminution in Metal salt solutions are then supplied dropwise 20 the rotational speed is of advantage from the to the filament, while being conducted 'over I point of view of simpler mounting. rollers, before it enters the. centrifuge. The

The subject of this invention is a process for metal Salt, of Commercial CuSOi tol 1 collecting artificial silk in the usual spinning litre of water, or? g. of commercial MgSO4 to 1 pots. The process consists in weighting the fine litre of water, interacts with the substances still 25v filaments in a suitable manner before introducremaining behind from the precipitation the tion into the spinning pot. Even in the case of products whereof are insoluble salts which pre extreme fineness, such weightedfilaments are cipitate on the filament and are only dissolved drawn smoothly into the spinning pot and are out again in the spinning pot, intothetop'of wound to a'perfectly satisfactory cake. I which acid is introduced. 3 0 g The weighting is best efiected by producing For forming the precipitate those quantities of a precipitate on the fibre, the freshly-spun filasalt solutions are preferably usedwhich are necment being treated with solutions of substances eSSary r interacting Wi h everytrace of the which react with the substances derived from Sub a p sent in the filament. The metal the precipitating bath to form an insoluble comsalt's ut s ed react t the c pp y pound. Those compounds which can interact to dIOXid-B Present i theyfilalment fl d ng. t0 the form comparatively heavy compounds are parfo w equations! a 1 I ticularly suitable. Thus, in the case of filaments Y e V of cuprammonium silk, salts of heavy metals 'i' v 40 which, under the influence of the ammonia and H O 40 copper still'contained in the filament, react to V V g '1,

form insoluble'basic salts or to form hydroxides g $g sb are particularly suitable. I In the case of viscose V 1 filaments, which leave the spinning bath charged The process, however, is limited neither, tothe with sulphuric acid or sulphate solutions, an cuprammonium oxide process nor to the salt after-treatment with soluble lead salts isparticsolutions mentioned byway. of example; on the. V

ularly advantageous. contrary, other processes and'other salt solutions 7 The present process also enables'satisfactory may also be employed. It is only necessary to:

spun cakes to be made in spinning pots of much choose those solutions which react with the sub- 50 diminished rotational speed when spinning artistances on the filament and precipitate insoluble 7 ficial silk filamentsof the usual titre. The speed substancespn the latter, thereby weighting the of rotation is smaller so that the spinning pot is filament, which insoluble substances are removed considerably protected. Also the power required only subsequently, after they have performed:

is strongly diminished and the mounting is fatheir task. r .55

f WhatlIclaimi s:"

' moving said insoluble 1. In the production'of aftificialsilk the steps of forming a thread of at most-60'deniers weighting said threadiby Water insoluble metallic com- 'poundsfcollecting'said thread in' the form of aj cake bya rotating spinning centrifugefiand-ra metallic compounds by suitable means. a V

I denier, the, step of weighting prem med 'ments with a water-insoluble, acid-soluble heavy in the centrifuge;

2. In'the manufacture of cuprainmo'nimn silk 1 the steps of forming a thread2ofuat 69f deniers, producing a precipitate of water insoluble metallic salts on said; thipeam; collecting v,t1 1e threadin' the form of a cakeLbysrmtinaspin; ning centrifuge, and dissolving the insoluble salts from thethread by suitable acid solutions materialgcollecting the weighted filament-sin a centrifuge and applyin acid to the cake iiormed 4; In the; preparation upon the filaments; collecting'ithe flIamentS in a.

' centrifuge and thereaftertreating"them ina solution which will dissolve the insoluble com pound.

In 7 the preparation o: artificial {silk-i of line 7 copper; and magnesium tov pmpitote on insoluwith} portion of the precipitating bath re- 0': artificial isuk prymie V denierfbyjthe cuprammonium process the 01-; treating the spun fll'aments with a materialwhich will react with the precipitatingf'solution- V. to: precipitate a heavy-water insoluble compound denier by the cup'rammoni'um prcce ssQthe steps of treating the spun filaments immediately after a leaving the spinning bath with asolution of asalt or one .of the metals of the group consisting of .blefsalt of the metal uponthe 'fildmenhicofiecting the filaments by centrifugal force and washing [them with an acid solution. I l

V 6. Inthe preparation of artificialfilamentsof fine deni'enyth'e steps comprising precipitating: a

water insoluble metallic" salt upon the formed V; fi1gments, collecting the filaments in a spinning 7 cakelhycentrifugal-iorceand thereafter remov-V ingthewater insoluble'compound. v 7.;Inkthe preparation of artificialfilaments of formed filaments with a compound which reactsfl I tained by the filaments to deposit a water insoluo 'bIe' metallic compound gqtner oms d theeafi r collecting thelfllaments-by cenmiugaljforce removing thein'solublecompmmd.- 1 j a: Ilrfl'lfi production or artiflcial maments' r miedenier, the" steps: comprising weightfiig" filaments with a waterinsoluble co lecting the filaments int the om or '9} a? rotating centrifuge and removing sem insoluble compound by-suitslole'means' I v r .7 15 v fine denier thesteps-comprising extruding the; a -fllam'ents irito al preoipitating bath, treatingvthe 

